#include "esp_http_server.h"
#include "esp_camera.h"

static const char* _STREAM_CONTENT_TYPE = "multipart/x-mixed-replace;boundary=" PART_BOUNDARY;
static const char* _STREAM_BOUNDARY = "\r\n--" PART_BOUNDARY "\r\n";
static const char* _STREAM_PART = "Content-Type: image/jpeg\r\nContent-Length: %u\r\n\r\n";

esp_err_t jpg_stream_httpd_handler(httpd_req_t *req){
    camera_fb_t * fb = NULL;
    esp_err_t res = ESP_OK;

    res = httpd_resp_set_type(req, _STREAM_CONTENT_TYPE);
    if(res != ESP_OK){
        return res;
    }

    while(true){
        fb = esp_camera_fb_get();
        if (!fb) {
            ESP_LOGE("MJPEG", "Camera capture failed");
            res = ESP_FAIL;
            break;
        }

        if(fb->format != PIXFORMAT_JPEG){
            bool jpeg_converted = frame2jpg(fb, 80, &_jpg_buf, &_jpg_buf_len);
            if(!jpeg_converted){
                ESP_LOGE("MJPEG", "JPEG compression failed");
                esp_camera_fb_return(fb);
                res = ESP_FAIL;
            }
        } else {
            _jpg_buf_len = fb->len;
            _jpg_buf = fb->buf;
        }

        if(res == ESP_OK){
            res = httpd_resp_send_chunk(req, _STREAM_BOUNDARY, strlen(_STREAM_BOUNDARY));
        }
        if(res == ESP_OK){
            size_t hlen = snprintf((char *)part_buf, 64, _STREAM_PART, _jpg_buf_len);
            res = httpd_resp_send_chunk(req, (const char *)part_buf, hlen);
        }
        if(res == ESP_OK){
            res = httpd_resp_send_chunk(req, (const char *)_jpg_buf, _jpg_buf_len);
        }

        if(fb->format != PIXFORMAT_JPEG){
            free(_jpg_buf);
        }
        esp_camera_fb_return(fb);
        if(res != ESP_OK){
            break;
        }
    }

    return res;
}

httpd_uri_t uri_get = {
    .uri       = "/stream",
    .method    = HTTP_GET,
    .handler   = jpg_stream_httpd_handler,
    .user_ctx  = NULL
};

void start_http_stream_server()
{
    httpd_config_t config = HTTPD_DEFAULT_CONFIG();
    httpd_handle_t server = NULL;
    if (httpd_start(&server, &config) == ESP_OK) {
        httpd_register_uri_handler(server, &uri_get);
    }
}